hi everyone , i have a felt f3 , and noticed a mark on my seat post ( carbonfibre) it looks like the clamp has left a small impression in the seatpost .the seat post clamp has maximum 5nm on the top bolt and 7nm on lower bolt which i did up to 4nm and 6nm respectively , the mark is only were the split in the clamp is , i use a tension wrench .i had a slight creak a little while back so removed the seatpost to apply some carbon paste and noticed the mark , i have since bought a deda seatpost and dont want to have it happen again .i have fitted it tonight and have only tightened the bolts to 2.5nm with paste , i havent taken it for a ride , what is the minimum bolt tesion people have used with no seat post slippage .has anyone else had simular issue .

The mark is deep worry me enough to get a new seatpost after seeing the thread on here about the poor bugger that had his post break and cut him up .On the clamp it has the maximum is 5nm on the top and 7nm on the lower bolt , i being aware of this only did them up to 4nm and 6nm on the old seatpost .The mark seems to be were the split is on the clamp as if the edge is cutting in to it , could be from the post rocking in the clamp .

scott w wrote:The mark seems to be were the split is on the clamp as if the edge is cutting in to it , could be from the post rocking in the clamp .

So you have bought a new post, but could the clamp be the cause? Is it clamping hard on the post instead of the mast? Do Deda have a matching clamp?I'd be sticking to the recommended torque. CF assembly compound will make a mess of the post if it slips.

The post never slipped , i only found it when i removed it as it had a creak coming from the post , it was tensioned to 4nm on the top and 6nm on the lower bolt , it does look to me like it may have been flexing in the top portion of the clamp .The max tension on the top bolt is 5nm so i thought 4 would be fine with paste .

One of my mates carbon seatpost snapped as he was riding along at 28kph on a flat hotmix road, and he fell backwards and landed on his head. That was actually lucky because a few minutes earlier he had made a 90kph descent on our nastiest mountain ... a crash there would have killed him. The seatpost had been adjusted by a bike shop the week before, it was obviously overtensioned.Ive also seen some nasty crashes caused by snapped stems and stem bolts. Cycling is risky enough without having this sort of equipment failure.For myself (my son's bikes), I have 2 rules:1. Aluminium seatposts only.2. Aluminium stems only with 4 titanium bolts, never 2.I'll put up with the extra 8.3 milligrams of weight to make sure these preventable accidents dont happen.